how to add up quantities in items spreadsheet?

[mikehende]

Hello, I received a product order from a retailer where he lists the quantities of each product he requires, I am trying to add up not the dollar amount of the total order but only the total quantity of his order, for example, he wants 2 of this, 3 of that, 5 of the other e.t.c, I am trying to use the auto sum feature after highlighting the entire quantities column but that is not working, help?